This invention pertains to the art of thermal torches and more particularly to consumable thermal torches or lances. The invention is particularly applicable to an oxygen lance typically employed for boring, cutting, burning, and the like of hard base materials and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications and may be advantageously employed in other environments and applications.
Commonly owned U.S. Pat. No. 4,114,863, which is hereby incorporated by reference, generally describes the background of a thermal torch in which hard base materials such as ferrous metal, slag, concrete and the like may be pierced or cut through due to the rapid, exothermic oxidation of iron in the presence of oxygen. Oxygen is supplied under pressure to one end of the thermal torch and is ignited at the other end for thermic reaction with the base material. Control of the pressure and amount of oxygen release from the ignited end, in turn, controls the thermic reaction of the torch for cutting and the like. The thermal torch is consumed by this reaction and, therefore, must be replaced from time to time with a new length of pipe or tubing.
U.S. Pat. No. 4,114,863 patent describes a marked improvement in the thermal torch art by which the so-called "splatter" problem, as well as flame spreading, is controlled. A pair of inner and outer casings define a first gas flow passage therebetween while the inner casing includes a plurality of elongated burning rods. The burning rods define a series of second gas flow passages in the inner casing for the primary thermic reaction. The center portion of the thermal torch is burned back approximately one half inch from the outer casing whereby the first gas flow passage forms a substantially continuous oxygen shield to limit the splattering at the thermic reaction site.
With renewed interest in use of thermal torches, it has been considered desirable to increase the temperature at which the thermic reaction takes place. An increase in thermic reaction temperature necessarily provides a wider spectrum of materials which may be cut. Additionally, a simplified method of forming the oxygen lance is always desired. Accordingly, the subject invention creates the highest exothermic reaction known in the industry through the enhancement of the benefits provided by the above-noted patented structure.